Electric-light pole



(No Model.)

A1a. THOMSON. ELECTRIC LIGHT POLE.

No. 398,040. Patented Nov. 20, 1888.

WITNESSES PATENT rines.

` ELU-1U THOMSON, OF LYNN, MASSACHUSETTS.

ELECTRIC-LIGHT POLE.

SPECIFICATION forming part f Letters Patent No. 393,040, dated November 2Q, 1888. Application fusa .nlm o, lese. semi No. 276,648. No monti.)

To all whom, it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented a certain new and useful Electric-Light Pole, of which the following is a specification.

My invention relates to the construction of posts or poles designed for supporting electric lines or conductors carrying currents of considerable tension.

The object of the invention is to so con'- struct the pole that a person mounting the post may be free from the danger ot' receiving a shock by forming a ground for the electric current through his body.

To this end my invention consists, essentially, in constructing the post or pole with a section interposed between itspedestal and its top or line-supporting portion and insulated from both, such section being of suflicient length to prevent a person ascending the pole from touching` the pedestal or base portion and the portion which supports the line wire or conductor at the same time.

My invention consists, further, in certain details of construction, to be more particularly hereinafter described, and then specified in the claims.

My invention consists, further, in the special constructions and combinations, which will be described in connection with the accompanying drawings, and then specified in the claims.

Referring to the drawings, Figure 1 is a side elevation of a post constructed in accordance with my invention. Fig. 2 is a vertical section through a form of joint which may bc employed. Fig. 3 is a vertical section through a modified form of joint. Fig. 4 is a vertical section through the intermediate portion of a post or pole of modified construction, but also embodying my invention.

In Fig. 1 the post is shown carrying an electric light supplied by current from a linewire, L.

A indicates the base or pedestal portion of the post, which may be conveniently made of cast-iron, and which is in connection with the ground.

C indicates the top or line-supporting portion, which part may be of greater or less length, as desired. interposed between these two portions is the section B, insulated both from the pedestal A and from the part which forms the upper portion of the post and supports the electric line. The intermediate section, B, should be of such length that a person ascending the post cannot,while in connection with the pedestal A, reach t-o the upper section, C. One intermediate section may be employed, as indicated at B, though it will be obvious that the intermediate section, B, might be divided into two or more sub-sections,

It will be found sufficient in practice to make the section B about seven feet in length.

The pole may be provided with steps, as usual, to facilitate ascent and descent in connection with the examination or rearrangement of the line or the apparatus supported by the post.

A form ofjoint which may be used between the sections B and C is shown in Fig. 2. One section, C, is cup-shaped at its lower end, and is made somewhat larger in diameter than the upper end of the section B, which it receives. The space between the two sections is iilled with an insulating or cementing compound, which can be cast in position, and may be formed, for instance, of a mixture of sulphur and sand, although obviously other materials may be employed.

To assist in the insulation, the lower end of lthe section C is made to form at F a depending ilange or water-shed to prevent the formation of a connection between the two sections by moisture in stormy or wet Weather. This iiange or water-shed may be conveniently se cured by applying the insulating compound in amount suliicient to only partially lill the space between the two sections at the joint.

In the modified form of joint indicated in Fig. 3 the insulating compound is cast so as to entirely inclose the upper end of the section B, thus preventing a possible short-circuiting or grounding by particles of metal or moisture which might gain access to the interior of the post when the latter is formed of pi pe or is made of any other material in whole sections.

IGO

Ido not limit myself to the special forms of tween the pedestal and line-supporting portions,such intermediate sections insulating the pedestal and top portions from one another.

It is obvious that the forms ofjoint shown in Figs. 2 and 8 might be used between the pedestal A and the next section, B.

In Fig. 4: the intermediate section,B, is shown as constructed of wood, which may or may not be covered with a sheath of iron. v It is prefer- Io able to apply in this case also a water-shed at one or bot-h joints. In the instance shown in Fig. 4it isobvious that it is not necessary to apply additional insulating material at the `joint between the sections.

I5 Any pleasing design maybe given tothe section of post.

An additional element ofsafety is secu red by making the extreme upper section entirely of wood.

2o Tests may be made from time to time of the insulation of the joints, especially in wet Weather, to afford a further safeguard.

'Ihesection C may support the line in any desired manner, and may, if desired, be provided with an attached tube or support, to

which the line is connected.

What I claim as my invention is- 1. A supporting post or pole for electric lines, having between its pedestal or earth por- 3o tion and its upper or wire-supporting portion one or more intermediate sections insulated from base and top, and of sufficient length to prevent a person from touching both pedestal and top sections simultaneously.

2. A sectional post or pole having at the joints noi' the insulated sections a depending flange or water-shed, as and for the purpose described.

3. An electric-line post or pole having an interposed section betweenits top and pedestal, insulating the one from the other, and of suffi cient length to prevent a person from touchmore su perposed sections,each having a socket at its lower end, and insulating or cementing material in said socket, as and for the purpose described.

7. A sectional electric-line post or pole having the end of one section which enters another entirely inclosed in insulating material, as and for the purpose described.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 21st day of May, A. D. 1888.

ELlHU THOMSON. Witnesses:

J. W. GIBBONEY, A. L. ROHRER. 

